The intervertebral disc’s (IVD) annulus fibrosus (AF) retains the hydrostatic pressure of the nucleus pulposus (NP), controls the range of motion, and maintains the integrity of the motion segment. The microstructure of the AF is not yet fully understood and quantitative characterization is lacking, leaving a caveat in modern medicine’s ability to prevent and treat disc failure (e.g., disc herniation). In this study, we show a reconstruction of the 3D microstructure of the fibers that constitute the AF via MRI diffusion tensor imaging (DTI) followed by fiber tracking. A quantitative analysis presents an anisotropic structure with significant architectural differences among the annuli along the width of the fibrous belt. These findings indicate that the outer annuli's construction reinforces the IVD while providing a sufficient degree of motion. Our findings also suggest an increased role of the outer annuli in IVD nourishment.
Bibliographical noteFunding Information:
The authors wish to thank the Dan David Foundation and The Tassia & Dr. Joseph Meychan Chair of the History and Philosophy of Medicine for funding this research. In addition, we wish to thank the Strauss Center for computational neuroimaging, the Sackler Institute of Biophysics, and the Israel Science Foundation for the purchase of the MRI system.
Funding was provided by Israel Science Foundation (Grant No. 1397/08).
© 2021, The Author(s).
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